Insulator apparatus for vacuum insulated tubing

ABSTRACT

An insulating apparatus for use with vacuum insulated tubing sting to reduce heat loss through the joints, where the apparatus includes an insulator adapted to surround the joint and a latching joint protector adapted to surround the insulator and hold the insulator against the joint, where the protector also includes a channel for receiving injection and/or control tubing. The insulator is capable of reducing heat loss through the joints of a vacuum insulated tubing string by as much as 95%.

RELATED APPLICATION

This application claims the benefit of provisional priority to UnitedStates Provisional Patent Application Ser. No. 60/434,903 filed 20 Dec.2002.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an insulator apparatus for vacuuminsulating tubing.

More particularly, the present invention relates to an insulatorapparatus for vacuum insulating tubing adapted to provide insulation atjoints in a vacuum insulating tubing string including an insulatingmember and a joint protector surrounding and holding the member in placeat the joints.

2. Description of the Related Art

In the petroleum industry, production tubing is disposed within aborehole for transporting oil and gas from subsurface bearing formationsto the surface. This tubing is comprised of elongate sections threadedtogether to form a production string, the joint thereby formed beingreferred to variously as a tool joint, coupling, or upset.

In conjunction with this production tubing, it is frequently necessaryto provide a system for delivering fluid media downhole. One reason maybe to permit the injection of chemical treatment fluids near theproducing formation for enhancing the production, for treatment ofdownhole conditions such as those involving undesirable corrosion, salt,or scale, and for delivery of corrosion or scale inhibitors,de-emulsifiers, or the like, downhole.

Yet another reason for providing these fluid delivery systems is for thetransmission of fluid pressure to various downhole valves or tools fromthe surface for purposes of control or the like. Thus, various forms ofinjection or control lines referred to hereinafter generally as tubingand having internal diameters much smaller than that of the productiontubing itself are provided which are disposed radially outward of andadjacent to the production tubing. In some cases the tubing is of anencapsulated variety wherein both the tubing and wire rope (whichprovides crush resistance from side forces) are encapsulated in anappropriate thermoplastic elastomer, whereas in other applications, thetubing may be of an unencapsulated or bare variety.

In other situations, electrical cables are routed downhole in likemanner to the tubing for monitoring pressure instruments or forproviding power for downhole motors or the like.

One problem with these tool joints and the associated tubing or cables(referred to hereinafter as tubing for convenience) is that they arefrequently subjected to damage from contact with surrounding casing orthe formation itself, such as when the production string is moved up ordown within the borehole. This damage may be due to abrasion orcompressive forces against the joint or tubing which often occurs as thetool joint is moved across a deviation in the borehole. Thus, means weresought for protecting this bare or unencapsulated tubing, cable and thetool joints from damage.

In deep water drilling operations, one difficulty in producing oil fromsuch deep wells is the loss of heat associated with the oil as it flowsout of the productive formation into the production tubing resulting inproportional increase in fluid viscosity and reduced well productivity.One answer to this vexing problem was the advent of vacuum insulatedtubing, which provides a vacuum break between the production tubing andthe outside world, greatly reducing heat loss as the productive fluid iscommunicated to the surface. However, heat loss is still a problem atthe joints of the tubing where, out of necessity, the joints are notinsulated and therefore heat can flow out of the joints to thesurrounding.

Thus, there is a need in the art for an apparatus that can be attachedto at the joints of vacuum insulated tubing insulating the joints fromthe outside world, while providing a protected conduit for productioncommunication cables or other production wirelines.

SUMMARY OF THE INVENTION

The present invention provides an insulator apparatus for use withvacuum insulated tubing strings, where the apparatus includes aninsulator adapted to insulate joints in the vacuum insulating tubingstring and a joint protector adapted to secure the insulator against thejoints, to protect the joints from damage during run in and run out andto provide a protected conduit adapted to receive injection or controltubing associated with the vacuum insulated tubing.

The present invention also provides an apparatus for protecting andinsulating joints in a vacuum insulated tubing string, where theapparatus includes an insulator sleeve having a longitudinal slit, asubstantially smooth outer surface, and an inner surface that conformsto an outer contour of the joint and to a portion of the tubing oneither side of the joint. The apparatus also includes a joint protectorhaving a first latching end and second latching end where the latchingends are adapted to secure the protector to the vacuum insulated tubingstring on both sides of the joint. The protector also includes a centerregion having a insulator retaining member or a plurality of insulatorretaining members, where the center region is adapted to hold theinsulator against the joint. The protector also includes a conduitadapted to receive injection or control tubing allowing injection and/orcontrol tubing to pass over the joint in a protected manner. Theinsulator can also include a strip of adhesive adapted to seal thelongitudinal slit. Alternatively, the slit can include an interlockingfastener. The insulator can also include a spiral slit with or withoutan associated fastener.

The present invention also provides an apparatus for protecting andinsulating joints in a vacuum insulated tubing string, where theapparatus includes an insulator sleeve having a longitudinal slit, asubstantially smooth outer surface, and an inner surface that conformsto an outer contour of the joint and to a portion of the tubing oneither side of the joint. The apparatus also includes a joint protectorhaving a first latching end and second latching end where the latchingends are adapted to secure the protector to the vacuum insulated tubingstring on both sides of the joint. The protector also includes a centerregion having a plurality of insulator retaining members, where thecenter region is adapted to hold the insulator against the joint. Theprotector also includes a conduit adapted to receive injection orcontrol tubing allowing injection and/or control tubing to pass over thejoint in a protected manner. The insulator can also include a strip ofadhesive adapted to seal the longitudinal slit. Alternatively, the slitcan include an interlocking fastener. The insulator can also include aspiral slit with or without an associated fastener.

The present invention also provides an apparatus for protecting andinsulating joints in a vacuum insulated tubing string, where theapparatus includes an insulator sleeve having a longitudinal slit, asubstantially smooth outer surface, and an inner surface that conformsto an outer contour of the joint and to a portion of the tubing oneither side of the joint. The apparatus also includes a joint protectorhaving a first latching end and second latching end where the latchingends are adapted to secure the protector to the vacuum insulated tubingstring on both sides of the joint. The protector also includes a centerregion having a plurality of insulator retaining members, where thecenter region is adapted to hold the insulator against the joint. Theprotector also includes a conduit adapted to receive injection orcontrol tubing allowing injection and/or control tubing to pass over thejoint in a protected manner. The insulator can also include a strip ofadhesive adapted to seal the longitudinal slit. Alternatively, the slitcan include an interlocking fastener. The insulator can also include aspiral slit with or without an associated fastener.

The present invention provides an apparatus including an insulatoradapted to conform to the outer contour of the joint and a portion ofthe tubing on either side of the joint and a protector including a pairof half-cylinder shaped sections which are interconnected at respectiveedges by an elongate piano-type hinge having a releasable pin. Theopposite edges are provided with a plurality of pin guide sectionsmatingly received by each other to define a pair of longitudinal pinslots when the protector is disposed about a tool joint. A pair ofmating tapered pins are provided for each slot whereby when the pins aredriven into their respective slots, the edges of the half-sectionscarrying the pin guides are drawn toward each other to effectprogressively tighter engagement of the protector about the tool jointand tubing in an interference fit. Half-sections of varying radii ofcurvature and pins of varying taper are provided, whereby a variety oftool joints having differing outer dimensions may be accommodated,resulting in an effective interference fit by substituting half-sectionsand pins of appropriate size. A window intermediate the pair of pinslots facilitates lower pin installation while providing for slightflexing of the protector about the tool joint to further accommodatedimensional variations thereof.

The present invention provides a protected and insulated vacuuminsulated tubing string including a vacuum insulated tubing stringhaving a plurality of vacuum insulated tubing sections interconnected byjoints and an insulating apparatus of this inventio associated with eachjoint.

DESCRIPTION OF THE DRAWINGS

The invention can be better understood with reference to the followingdetailed description together with the appended illustrative drawings inwhich like elements are numbered the same:

FIGS. 1A–F depict views of a preferred embodiment of the insulatingapparatus of this invention detachably affixed to a joint of a vacuuminsulated tubing string;

FIG. 1G depicts a cut away view of an insulator of this invention havinga lower surface that conforms to a recess in the joint of a vacuuminsulated tubing string;

FIGS. 2A–F depict views of another preferred embodiment of theinsulating apparatus of this invention detachably affixed to a joint ofa vacuum insulated tubing string;

FIGS. 3A–F depict views of another preferred embodiment of theinsulating apparatus of this invention detachably affixed to a joint ofa vacuum insulated tubing string;

FIGS. 4A–D depict views of another preferred embodiment of theinsulating apparatus of this invention detachably affixed to a joint ofa vacuum insulated tubing string; and

FIGS. 5A–F depict other preferred embodiment of insulators of thisinvention.

DETAILED DESCRIPTION OF THE INVENTION

The inventors have found that heat loss from joints of a vacuuminsulated tubing string can be reduced by as must as 95% or more bydetachably affixing to each joint an insulating apparatus including aninsulator adapted to conform to an outer surface of the joint andpreferably to conform to a portion of the tubing on either side of eachjoint and a joint/insulator protector adapted to be interference fit tothe tubing on either side of each joint, to secure the insulator inplace and to provide a protected conduit for injection and controltubing. Thus, the inventors have found that a vacuum insulated tubingstring can be formed including an insulator protector of this inventionassociate with each joint in the string reducing heat loss through thejoints by as much as 95%.

The present invention broadly relates an insulator apparatus for usewith vacuum insulated tubing strings, where the apparatus includes aninsulator adapted to insulate joints in the vacuum insulating tubingstring and a joint protector adapted to secure the insulator against thejoints, to protect the joints from damage during run in and run out andto provide a protected conduit adapted to receive injection or controltubing associated with the vacuum insulated tubing.

The present invention broadly relates to a method for reducing heat lossat joint in a vacuum insulated tubing string including the step ofdetachably affixing to each joint of the string an insulator apparatusfor use with vacuum insulated tubing strings, where the apparatusincludes an insulator adapted to insulate joints in the vacuuminsulating tubing string and a joint protector adapted to secure theinsulator against the joints, to protect the joints from damage duringrun in and run out and to provide a protected conduit adapted to receiveinjection or control tubing associated with the vacuum insulated tubing.

The present invention broadly relates to a vacuum insulated tubingstring including a vacuum insulated tubing string having a plurality ofvacuum insulated tubing sections interconnected by joints and aninsulating apparatus of this invention associated with each joint.

Suitable polymers for making the insulators of the present inventioninclude, without limitation, insulating polymeric and/or ceramicmaterials. Preferred polymeric materials include, without limitation,thermal setting resins, thermoplastic elastomers, thermoplastics, or anyother polymeric material or mixtures or combinations thereof, where thepolymers good insulating properties and can be cast or molded by anystandard casting or molding technique including traditional polymercasting, traditional molding, rotary molding, injection molding, or thelike. Moreover, for structural plastics, the insulator can be cut usingtraditional cutting techniques. Preferred thermal setting resins includepolyurethanes, elastomers, or the like. Preferred thermoplastics includestructural plastics such as structure polyolefins exemplified byplastics such as high density polyethylene, polypropylene, polybutylene,polystyrenes, polyesters, polyurethanes, polyvinylchlorides,polyacrylates, nylons and other polyamides (Kevlar, Nomex), or the like.Preferred polyacrylates includes acetal resins such as Delrin® fromDuPont or other similar injection moldable polymers. The polymers shouldhave a thermal conductivity at or below about 0.5 W/m° C. at 100° C.,preferably at or below about 0.4 W/m° C. at 100° C., and particularly ator below about 0.3 W/m° C. at 100° C. Exemplary polyurethanes includeprecision urethane with short hardnesses of 45A to about 100A includingurethanes available from the manufacturers listed on the world wide webat urethane-ez.com/urethane. Preferred urethane polymers should have atensile strength between about 4,000 psi and about 14,000 psi at 75° F.,a 100% modulus of elasticity at 75° F. between about 1,000 psi and about550,000 psi, and an elongation of about at 75° F. between about 30% and1000. Particularly preferred urethanes have the physical characteristicslisted in Table IA–B.

TABLE IA Physical Properties of Preferred Urethanes Urethane 90A PPGUrethane 90A PTMEG Property 0° 75° 150° F. 0° 75° 150° F. Modulus, 41421083 967 1194 1140 956 100%, psi Modulus, 5009 1673 1303 1701 1612 1241200%, psi Modulus, 2530 2528 2416 1600 300%, psi Tensile 5851 3167 17647244 5446 2025 Strength, psi % Elongation 263 330 293 393 396 332 Die CTear, psi 660 189 126 390 306 220 Trouser Tear, 188 48 23 108 66 27 psiBashore 29 43 Resilience, % Compression 31 24 Set, % (Method B)Compression 32 57 Stress @ 1%, psi Modulus of N/A 3559 Rigidity, psiYoung's 6800 5097 Modulus, psi Shear Modulus, N/A 1700 psi Bulk Modulus,N/A 9.9 × 10³ psi Poisson's Ratio 0.475 0.499

TABLE IB Specific Heat and Thermal Conductivity Properties of thePreferred Urethanes Urethane 90A PPG Urethane 90A PTMEG Specific HeatTemperature Heat Flow Temperature Heat Flow ° C. J/kg · ° C. ° C. J/kg ·° C. 20 −1729 10 −1544 40 −1803 30 −1669 60 −1844 50 −1690 80 −1897 70−1716 100 −1913 90 −1720 120 −1907 100 −1710 140 −1885 130 −1713 ThermalConductivity Temperature Conductivity Temperature Conductivity ° C. W/m· ° C. ° C. W/m · ° C. 100 0.276 60.4 0.208 125 0.266 68.5 0.202 1500.259 100.7 0.213 175 0.253 126.9 0.215

Suitable materials out of which the protectors of this invention can bemade include, without limitation, metals especially iron alloys such asforged steel, stainless steel, or the like. Generally, the insulatorsare desinged to decrease heat loss from the joint of a vacuum insulatedtubing by 50% or more, preferably, by 75% or more, particularly, by 85%or more and especially by 90% or more.

Insulating Apparatus for Recessed Jointed Vacuum Insulated Tubing

Referring now to FIGS. 1A–F, a preferred embodiment of an insulatingapparatus, generally 100, of this invention is shown detachably affixedto a joint 102 of a vacuum insulated production string 104. The string104 is shown with a first string section 106 a and a second stringsection 106 b. The tube sections 106 a&b include inner tubes 108 b&b andouter tubes 110 a&b with vacuum gaps 112 a&b interposed therebetweenexcept at the joint 102 where the outer tubes 110 a&b end forming arecessed area 114. The joint 102 is formed from a male connector 116formed out of a distal end 118 of the inner tube 108 a of the first tubesection 106 a and a female connector 120 formed out of a proximal end122 of the inner tube 108 b of the second tube section 106 b. Becausethe joint 102 does not include a vacuum gap, heat can flow from aninterior 124 of the string 104 to the surroundings, a problem to beavoided and a problem solved by the apparatuses of this invention.

The insulating apparatus includes an insulator 140 and a latchingprotector 160. The insulator 140 comprises a cylinder sleeve 142 havinga longitudinal slit 144 where the slit 144 allows the sleeve 142 to beopened and fitted into the recess 114. The slit 144 can be left as is orcan be sealed by an insulating sealing compound such as a fast dryingthermoplastic, thermosetting resin, other polymeric insulating materialor mixtures or combinations thereof. Although the sleeve 142 of FIGS.1A–F is cylindrical with straight edges 146, the sleeve 142 can bedesigned to conform to the recess 114 so that its edges 146 are nowtapered as shown in FIG. 1G.

The protector 160 includes two hinges 162, a raised portion 164separating the two hinges 162, two arcuate sections 166 and aninterdigitated latch 168 having a first end 170 and a second end 172adapted to receive a key 174, which locks the protector 160 in placewith an interference fit. The latch 168 and key 174 are defined in moredetail in U.S. Pat. No. 4,615,543, incorporated therein by reference.When the protector 160 is placed around the insulator 140 and closed,the key 174 is inserted into the interdigitated latch 168 in such a waythat the key 174 pulls the latch 168 together creating an interferencefit against the insulator 160 and/or the sections 106 a&b. The raisedportion 164 forms a protected channel 176 adapted to receive injectionand/or control tubing, lines, or cables 178 and can include a cushion180 on its inner surface 182.

Referring now to FIGS. 2A–F, another preferred embodiment of aninsulating apparatus, generally 200, of this invention is showndetachably affixed to a joint 202 of a vacuum insulated productionstring 204. The string 204 is shown with a first string section 206 aand a second string section 206 b. The tube sections 206 a&b includeinner tubes 208 b&b and outer tubes 210 a&b with vacuum gaps 212 a&binterposed therebetween except at the joint 202 where the outer tubes210 a&b end forming a recessed area 214. The joint 202 is formed from amale connector 216 formed out of a distal end 218 of the inner tube 208a of the first tube section 206 a and a female connector 220 formed outof a proximal end 222 of the inner tube 208 b of the second tube section206 b. Because the joint 202 does not include a vacuum gap, heat canflow from an interior 224 of the string 204 to the surroundings, aproblem to be avoided and a problem solved by the apparatuses of thisinvention.

The protector 260 includes two latching ends 262 having two hinges 264,a raised portion 266 separating the two hinges 264, and outer tubeengaging members 268. The protector 260 also includes longitudinallyextended arcuate sections 270 interconnecting the latching ends 262 andthe latching ends 262 also include an interdigitated latch 272 having afirst digitated end 274 and a second digitated end 276 adapted toreceive a key 278, which locks the protector 260 in place with aninterference fit. The latches 272 and keys 278 are defined in moredetail in U.S. Pat. No. 4,615,543, incorporated therein by reference.When the protector 260 is placed around the insulator 240 and joint 202and closed, the keys 278 are inserted into the interdigitated latches272 in such a way that the keys 278 pull the latches 272 togethercreating an interference fit against the string 202 on each side of eachjoint. The raised portion 266 forms a protected channel 280 adapted toreceive injection and/or control tubing, lines, or cables 282 and caninclude a cushion 284 on its inner surface 286.

Insulating Apparatus for Raised Jointed Vacuum Insulated Tubing

Referring now to FIGS. 3A–F, another preferred embodiment of aninsulating apparatus, generally 300, of this invention is showndetachably affixed to a joint 302 of a vacuum insulated productionstring 304. The string 304 is shown with a first string section 306 aand a second string section 306 b. The tube sections 306 a&b includeinner tubes 308 b&b and outer tubes 310 a&b with vacuum gaps 312 a&binterposed therebetween except at the joint 302 where the outer tubes310 a&b end forming a recessed area 314. The joint 302 is formed from ajoint collar 316 having two female end connectors 318 adapted to receivemale connectors 320 associated with the tube sections 306 a&b. The jointcollar 316 is larger than the section 306 a&b forming a raised jointsection 322. Because the joint 302 does not include a vacuum gap, heatcan flow from an interior 324 of the string 304 to the surroundings, aproblem to be avoided and a problem solved by the apparatuses of thisinvention.

The insulating apparatus includes an insulator 340 and a latchingprotector 360. The insulator 340 comprises a cylinder sleeve 342 havinga longitudinal slit 344. The sleeve 342 also includes a groove 346adapted to conform to the raised joint section 322 of the joint 302. Thesleeve 342 also includes end portions 348 that extend past the jointcollar 316 over portions 350 of the section 306 a&b, where the portions350 extend out a sufficient distance from the joint 302 to provideimproved joint insulation, where the sufficient distance is at leastsufficient to extend past the start of the vacuum gaps 310 a&b of thesection 306 a&b. The slit 344 allows the sleeve 342 to be opened andfitted into the recess 314. The slit 344 can be left as is or can besealed by an insulating sealing compound such as a fast dryingthermoplastic, thermosetting resin, other polymeric insulating materialor mixtures or combinations thereof.

The protector 360 includes two latching ends 362 having two hinges 364,a raised portion 366 separating the two hinges 364, and outer tubeengaging members 368. The protector 360 also includes longitudinallyextended members 370 interconnecting the latching ends 362. The latchingends 362 also include interdigitated latches 372, each latch 372 havinga first digitated end 374 and a second digitated end 376 adapted toreceive a key 378, which locks the protector 360 in place with aninterference fit. The latches 372 and keys 378 are defined in moredetail in U.S. Pat. No. 4,615,543, incorporated therein by reference.When the protector 360 is placed around the insulator 340 and joint 302and closed, the keys 378 are inserted into the interdigitated latches372 in such a way that the keys 378 pull the latches 372 togethercreating an interference fit against the string 302 on each side of eachjoint. The raised portion 366 forms a protected channel 380 adapted toreceive injection and/or control tubing, lines, or cables 382 and caninclude a cushion 384 on its inner surface 386.

Alternate Protector Design

Referring now to FIGS. 4A–D, another preferred embodiment of aninsulating apparatus, generally 400, of this invention is shown toinclude detachably affixed to a joint (not shown) of a vacuum insulatedproduction string 402 within a cased well 404. The insulating apparatusincludes an insulator 440 and a latching protector 460. The insulator440 comprises a cylinder sleeve 442 having a longitudinal slit 444 wherethe slit 444 allows the sleeve 442 to be opened and fitted over eachjoint of the string 402. The slit 444 can be left as is or can be sealedby an insulating sealing compound such as a fast drying thermoplastic,thermosetting resin, other polymeric insulating material or mixtures orcombinations thereof. Moreover, as shown below the slit does not have tobe straight and can be formed with fastening or interlocking ends.

The protector 460 includes two latching ends 462 having two hinges 464,an arcuate portion 466 separating the two hinges 464, and outer tubeengaging members 468. The protector 460 also includes four substantiallyparallel, longitudinally extended members 470 interconnecting thelatching ends 462 so that the insulator 440 is held in place by the fourmembers 470. The latching ends 462 also include interdigitated latches472, each latch 472 having a first digitated end 474 and a seconddigitated end 476 adapted to receive a key 478, which locks theprotector 460 in place with an interference fit. The latches 472 andkeys 478 are defined in more detail in U.S. Pat. No. 4,615,543,incorporated therein by reference. When the protector 460 is placedaround the insulator 440 and joint 402 and closed, the keys 478 areinserted into the interdigitated latches 472 in such a way that the keys478 pull the latches 472 together creating an interference fit againstthe string 402 of either side of each joint. The arcuate portion 466forms a protected channel 480 adapted to receive injection and/orcontrol tubing, lines, or cables 482 and can include a cushion 484 onits inner surface 486. The protector 460 also includes a raisedinjection and/or control tubing conduit 488 also interconnecting the twoends 462. Thus, the member 470 and the conduit 488 structurally hold thetwo ends 462 of the protector 460.

Alternate Insulator Designs

Referring now to FIGS. 5A–F, several other preferred embodiment ofinsulators 500 of this inventor are shown. Looking at FIG. 5A, theinsulator 500 includes a zig-zagged slit 502. Looking at FIG. 5B, theinsulator 500 includes a spiral slit 504. Looking at FIG. 5C, theinsulator 500 includes a slit 506 having a fastener 508. The fastener508 includes a male connector 510 associated with a first end 512 of theinsulator 500 and a female connector 514 associated with a second end516 of the insulator 500. Looking at FIG. 5D, the insulator 500 includesa slit 518 having a fastener 520. The fastener 520 includes an innerlongitudinal lip 522 associated with a first end 524 of the insulator500 and an outer longitudinal lip 526 associated with a second end 528of the insulator 500. Looking at FIG. 5E, the insulator 500 includes aslit 530 having a fastener 532. The fastener 532 includes an innerlongitudinal lip 534 having a longitudinal groove 536 associated with afirst end 538 of the insulator 500 and an outer longitudinal lip 540having a longitudinal indentation 542 associated with a second end 544of the insulator 500. Looking at FIG. 5F, the insulator 500 includes aslit 546 having an interlocking fastener 548. The interconnectingfastener 548 includes an inner longitudinal lip 550 having longitudinalgrooves 552 associated with a first end 554 of the insulator 500 and anouter longitudinal lip 556 having longitudinal indentations 558associated with a second end 560 of the insulator 500, where the grooves552 are designed to receive the indentations 558 to form a lockingfastener. Although several insulators with slit ends designed to engageeach other in a substantially gap free manner have been described, anyother fastening or means for bring the slit end together in asubstantially gap free manner.

All references cited herein are incorporated by reference. While thisinvention has been described fully and completely, it should beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described. Although theinvention has been disclosed with reference to its preferredembodiments, from reading this description those of skill in the art mayappreciate changes and modification that may be made which do not departfrom the scope and spirit of the invention as described above andclaimed hereafter.

1. An insulating apparatus for insulating joints of a vacuum insulatedtubing string comprising: an insulator adapted to surround joints of thevacuum insulated tubing string, where the insulator comprises: acylindrical sleeve including: a longitudinal slit, a substantiallystraight outer surface, an inner surface having a joint conformingmiddle section, and wings conforming to portions of the string on eitherside of the joint and extending out away from the joint a sufficientdistance to overlap with a section of the string that includes a vacuumgap between an inner tube and an outer tube of the string, and alatching joint protector adapted to surround the insulator and hold theinsulator against the joint and including a channel for receivinginjection tubing, control tubing or a combination of injection andcontrol tubing.
 2. The apparatus of claim 1, wherein the slit is azig-zagged slit.
 3. The apparatus of claim 1, wherein the slit is aspiral slit.
 4. The apparatus of claim 1, wherein the slit includeshaving a fastener comprising a male connector associated with a firstend of the sleeve and a female connector associated with a second end ofthe sleeve.
 5. The apparatus of claim 1, wherein the slit includes afastener comprises an inner longitudinal lip associated with a first endof the sleeve and an outer longitudinal lip associated with a second endof the sleeve.
 6. The apparatus of claim 1, wherein the slit includes afastener comprising an inner longitudinal lip having a longitudinalgroove associated with a first end of the sleeve and an outerlongitudinal lip having a longitudinal indentation associated with asecond end of the sleeve.
 7. The apparatus of claim 1, wherein the slitincludes an interlocking fastener comprising an inner longitudinal liphaving longitudinal grooves associated with a first end of the sleeveand an outer longitudinal lip having longitudinal indentationsassociated with a second end of the sleeve, where the grooves aredesigned to receive the indentations to form a locking fastener.
 8. Amethod for reducing heat loss from a vacuum insulated tubing stringcomprising the step of detachably affixing to each joint of the stringan insulating apparatus comprising an insulator adapted to surround thejoint and a latching joint protector adapted to surround the insulatorand hold the insulator against the joint, where the protector alsoincludes a channel for receiving injection and/or control tubing.
 9. Themethod of claim 8, wherein the insulator comprises a cylindrical sleeveincluding a longitudinal slit.
 10. The method of claim 8, wherein theinsulator comprises a cylindrical sleeve including a longitudinal slit,a substantially straight outer surface and an inner surface conformingto an outer surface of the joint.
 11. The method of claim 8, wherein theinsulator comprises a cylindrical sleeve including a longitudinal slit,a substantially straight outer surface and an inner surface conformingto an outer surface of the joint and to portions of the string on eitherside of the joint.
 12. The method of claim 8, wherein the insulatorcomprises a cylindrical sleeve including a longitudinal slit, asubstantially straight outer surface and an inner surface having a jointconforming middle section and wings conforming to portions of the stringon either side of the joint and extending out away from the joint asufficient distance to overlap with a section of the string including avacuum gap between an inner tube and an outer tube of the string. 13.The method of claim 9, wherein the slit is a zig-zagged slit.
 14. Themethod of claim 9, wherein the slit is a spiral slit.
 15. The method ofclaim 9, wherein the slit includes having a fastener comprising a maleconnector associated with a first end of the sleeve and a femaleconnector associated with a second end of the sleeve.
 16. The method ofclaim 9, wherein the slit includes a fastener comprises an innerlongitudinal lip associated with a first end of the sleeve and an outerlongitudinal lip associated with a second end of the sleeve.
 17. Themethod of claim 9, wherein the slit includes a fastener comprising aninner longitudinal lip having a longitudinal groove associated with afirst end of the sleeve and an outer longitudinal lip having alongitudinal indentation associated with a second end of the sleeve. 18.The method of claim 9, wherein the slit includes an interlockingfastener comprising an inner longitudinal lip having longitudinalgrooves associated with a first end of the sleeve and an outerlongitudinal lip having longitudinal indentations associated with asecond end of the sleeve, where the grooves are designed to receive theindentations to form a locking fastener.